Superposed enamel



J. G. G. FROST SUPERPOSED ENAMEL Filed June 21,1928 7 Sept. 6, 1932.

De .s/yn E namel z W 7 a m MW n y a E D e 5 a B INVENTOR John G. G.Fr0sv ATTORNEYS Shae) Si-eel Patented Sept. 6, 1932 JOHN G. G. FROST, DI -CLEVELAND, OI IIO, ASSIGNOR 1'0 THE VITBEOUS ERA-IDLING commemorcnnvnnann, 01110, A. coaeona'rron or 01:10

' surnarosnn ENAMEL Application filed June 21,

This invention relates to vitreous enameling, and more particularly to a methodof and means fordisposing enamel upon surfaces such as of sheet steel.

In the past, in producing vitreous enameled surfaces having vitreous enameled designs thereon, it has been ordinarily the practice to burn an enamel coating upon the surface as a whole, and subsequently to spray upon the section of the surface-to be decorated an aqueous suspension of suitably colored enamel. This colored enamel has been permitted to dry thoroughly, whereupon excess enamel has been brushed off to leave a remainder of the desired configuration. This design enamel has then been burned and any additional colored enamel or enamels similarly in-' dividually applied and burned. It has not ordinarily been possible with such aqueous; suspensions satisfactorily to form a design by spraying through a stencil.

An object of this invention is to provide an advantageous method for disposing enamel I upon surfaces to be vitreous enameled. Other objects of my invention are to provide a method for disposing enamel upon a surface whereby such enamel will dry extremely rapidly without running or dripping. Other objects are to provide a method whereby designs consisting of several colors maybe disposed upon a surface without requiring a burning operation after each application of colored enamel.- A further object is to'provide a method whereby a vitreous enameled article including colored designs may be formed without requiring burning of the base Enamel coating before application of the esign.

Other objects will be apparent to those skilled in the art from the disclosures herein ma e. i

a .By my invention I associate the enamel frit to be employed for application to the surface to be enameled with an organic binder which may preferably be dissolved in a rapid drying or volatile solvent. This association, to give thorough mixing, is preferably accom plished by grinding the materials composing the frit 1n the binder. vI have found that' l by such grinding, the frit and the binder are 1928. Serial No. 887,855.

most readily hand. i n

' The consistency of the suspension will depend in part upon the mode of application of the enamel to the surface. Thus, for application of the enamel through a stencil by means of a brush, the suspension is referably of a fairly thick consistency. F cr a plication of the enamel by free hand hrus ing, the suspension is preferablyof a consistency to permit some degree of flow of the enamel, as inthe case of the brushing of paint.

For application by spraying, and in particular forapplication by spraying through a stencil and in the formation of designs consisting of several colors, the suspension preferably includes a sufliciently rapid drying or volatile solvent to cause the suspension to dry very rapidly, and without running or dripping. of the dissolved organic binder employed, which binder will be hereinafter more fully disclosed, the enamel suspension dries'substantially immediately without any running or dripping, whereby the enamel conforms exactly to the configuration desired, thus By virtue of the characteristics associated for the purpose in eliminating any necessity for'wiping. Other colored enamels may be subsequently applied to. the article until the design is completed.

Since no wiping of the added enamel is necessary, the added color or colors may be disposed upon a base coat of enamel before said base coat is burned. The base coat and the subsequently disposed portions of colored enamel may thus be vitrified in one burning. It may be convenient, however, to apply the design enamel, which may consist of several colors, to a burned enamel surface. In such case, of course, any accidentally applied excess design enamel may be readily removed to correct the design without requiring the re-application of enamel to the entire surface. A convenient method of applying the colored enamel is illustrated in the accompanying drawing, in which Figure 1 is a plan view of an enameled steel sheet, showing a method of applying a ppr tion of a colored design through a stencil;

Fig. 2 is a similar view showing the method surface 2. It will, of course,

of applying another portion of the design through a diflerent stencil; Fig. 3 is a plan view of plate provided with a multi-colored enamel design; and

Fig. 4 is a fragmentary, enlarged crosssectional view on the line 44 of Fig. 3. v

Referring to the drawing, the numeral 1 designates a steel plate upon which a layer of enamel 2 is applied. In applying a multicolored design upon the enameled surface a stencil 3 having a cut-out portion 4 of the desired configuration is superimposed upon the enameled surface 2 and enamel of the desired color is sprayed through the openings in the stencil upon the enameled surface. Stencil 3 is then removed and a stencil 5 having cut-out portion 6 of a diflerent configuration is placed upon the enameled surface and an enamel of a different color is sprayed through the opening of the stencil 5 to form the remainder of the design. By utilizing such a method it will be apparent that a multi-colored design 7 of any desired configuration may be applied to the enameled be understood that instead of sprayingthe colored enamel through the openings in the stencil it may be applied by any suitable means, such as by brushing, and if desired a single color may be employed, in which case it will only be necessary to utilize one stencil, or, if preferred, different colors may be applied throu h different openings in the same stenci v In certain cases, I may carry out my invention by applying an organic binder to the surface to be coated, dusting or otherwise disposing a dry comminuted enamel upon said binder-coated surface, and subsequently vitri 'ng said applied enamel.

of this disclosure,

- may be employed During'the urning of the enamel the organic binder is substantially completely burned out, leaving no residue which mate rially afl'ects the color or constituency of the enamel.

Various materials may be employed to form the dissolved organic binder contemplated by this invention. By way of example, and without limiting the generahty I have found satisfactory the use of a nitrocellulose lacquer such as of the type comprising nitrocellulose or a derivative thereof dissolved in butyl alcohol, acetone or other suitable solven As solvents various materials such\ as methyl, ethyl or butyl alcohol, acetone, or diethylene glycol. r 7

It will be seen that I have provided an advantageous and economical method of disposing enam 1 upon .surfaces to be vitreous enameled.-

It will also be noted that I have provided a method whereby vitreous enamel may be advantageously applied to sheet metal such an enamel steelv as sheet steel, to cover-the surface of said metal wholly or in part, and with one or more complete or partial layers.

It will further be noted that by my invention enamel may be applied as by spraying to form layers having indefinite borders, or designs having edges intermerging with a base coat of enamel. Furthermore, by my invention enamel may be readily sprayed through stencils to form designsof sharply defined characteristics or otherwise. Moreover, design portions of various colors may be applied serially without delay before the application of each subsequent design portion. In addition, configurations including several colors may be formed upon a surface without requiring the burning of the enamel of one color before the application of another color, whereby the colored enamels constituting the design may be vitrified in a single burn-ing operation.

It will further be seen that by my invention the amount of labor involved in disposing designs on articles to be vitreous enameled is materially reduced. Furthermore, a material decrease in drying time and number of burnings may be effected.

To those skilled in the art many modifica- Y tions of and widely differing embodiments and applications of my invention will suggest themselves, without departing from the spirit and scope thereof. My disclosures and the descriptions herein are purely illustrative and are not intended to be in any sense limiting.

What I claim is:

1. The method of vitreous enameling, which comprises spraying a suspension of vitreous enamel in a binder dissolved in a highly volatile solvent upon a coated surface in desired configuration and permitting said solvent to evaporate without the application of heat to the objectto be enameled, whereby said enameled coatings may be burned in one operation.

2. The method of vitreous enameling, which comprises applying a suspension of vitreous enamel in a binder dissolved in an organic solvent to a dry, unburned enamelcoated surface and permitting the fluid portion of said suspension to eva orate before lateral spreading of the superposed enameled coat over the underlying enamel portions can occur, whereby, clear-cut unsmeared enameled designs may be produced;

3. The method of vitreous enameling,

which comprises applying a fluid suspension of vitreous enamel in a binder dissolved in an organic solvent to a surface to be coated and permitting the fluid portion of said suspension to evaporate before lateral spreading of the superposed enamel over the underlying surface can take place, whereby said-enamel may be applied to conform-to any desired contour.

4. The method of vitreous enam'eling,

dry, unburned enamelwhich comprises applying a suspension of vitreous enamel in a cellulosic binder dissolved in a volatile solvent through a stencil upon a dry, unburned enamel-coated surface, per- I mitting said volatile solvent to evaporate rapidly, whereby lateral spreading of the superposed enamel over the underlying enamel surface cannot take place and whereby sharp definition between the two enamel surfaces may be had.

5. The method of vitreous enameling, which comprises applying a suspension of vitreous enamel in a. binder dissolved in a highly volatile solvent to an enameled surface in desired configuration, and permitting said solvent to evaporate rapidly whereby said applied enamel may retain said configuration, and vitrefying said applied enamel.

,6. The method of forming multicolored vitreous enamel designs, which comprises serially applying suspensions of each colored vitreous enamel in a binder dissolved in a highly volatile solvent upon a surface in desired configuration to formseparately the portions of the design of each color, permitting the volatile-solvent of each suspension to evaporate rapidly before the application of the next subsequent suspension, and vitrefying the enamel of the design in a single burning operation.

7. The method of forming multicolored vitreous enamel designs, which comprises spraying a suspension of colored vitreous enamel in a binder dissolved in a highly volatile solvent through a stencil to form the portion of the design to be constituted of that color, permitting said volatile solvent to evaporate rapidly whereby additional design portions may be substantially immediately applied,-repeating the o eration for each additional color of the esign, and vitrefying the enamel of the design in one burning opera tion.

8. The method of vitreous enameling, which comprises applying a fluid suspension of vitreous, enamel in a binder of cellulosic material dissolved in a volatile solvent to an :enameled'surface in the desired configuration, permitting said solvent to evaporate, and vitrefying the applied enamel.

In testimony whereof I aflix my signature.

JOHN G. G. FROST. 

